1. Field of the Invention
This invention pertains to winch drive and braking mechanisms and, more particularly, to improvements in a total winch drive and brake system, as well as the improvements in components thereof.
2. Description of the Prior Art
Conventional winches require the brake and clutch to by synchronized by controls to prevent the load from dropping. This requires added expense in manufacturing and maintenance and can cause an accidental dropping of the load if this synchronization is not maintained.
In vehicular-mounted winches for use in log skidding and the like, the workmen must be able to pull the cable from the winch drum to reach remote locations from the winch. A problem has always been how to first eliminate the inherent friction and hydraulic oil drag in a winch drive to allow free pulling of the cable and to be sure that the winch controls are always prevented from accidentally putting the winch prematurely into a free-spool condition. On the other hand, it is desirable to provide some drag on the drum when intentionally dropping a load to prevent overrunning of the drum or snarling of the tightly wound cable on the drum.
Winch drive controls to provide a safe free-spool operation are expensive and have utilized continuously flowing fluid, generally a very low-pressure fluid from a separate pump or from a diverted portion of the power fluid for the winch.
A common problem in oil-immersed driving elements is that the viscous oil movement causes the output of the drive to creep or move. Various drag brakes have been utilized to prevent such movement.